﻿#define _CRT_SECURE_NO_WARNINGS 1

#include<iostream>

using namespace std;


template<class K>
struct BSTNode
{
	K _key;
	BSTNode<K>* _left;
	BSTNode<K>* _right;
	BSTNode(const K& key)
		:_key(key)
		, _left(nullptr)
		, _right(nullptr)
	{}
};
// Binary Search Tree
template<class K>
class BSTree
{
	typedef BSTNode<K> Node;
public:
	bool Insert(const K& key)
	{
		if (_root == nullptr)
		{
			_root = new Node(key);
			return true;
		}
		Node* parent = nullptr;
		Node* cur = _root;
		while (cur)
		{
			if (cur->_key < key)
			{
				parent = cur;
				cur = cur->_right;
			}
			else if (cur->_key > key)
			{
				parent = cur;
				cur = cur->_left;
			}
			else
			{
				return false;
			}
		}
		cur = new Node(key);
		if (parent->_key < key)
		{
			parent->_right = cur;
		}
		else
		{
			parent->_left = cur;
		}
		return true;
	}
	bool Find(const K& key)
	{
		Node* cur = _root;
		while (cur)
		{
			if (cur->_key < key)
			{
				cur = cur->_right;
			}
			else if (cur->_key > key)
			{
				cur = cur->_left;
			}
			else
			{
				return true;
			}
		}
		return false;
	}
	bool Erase(const K& key)
	{
		Node* parent = nullptr;
		Node* cur = _root;
		while (cur)
		{
			if (cur->_key < key)
			{
				parent = cur;
				cur = cur->_right;
			}
			else if (cur->_key > key)
			{
				parent = cur;
				cur = cur->_left;
			}
			else
			{
				// 0-1个孩⼦的情况
				// 删除情况1 2 3均可以直接删除，改变⽗亲对应孩⼦指针指向即可
				if (cur->_left == nullptr)
				{
					if (parent == nullptr)
					{
						_root = cur->_right;
					}
					else
					{
						if (parent->_left == cur)
							parent->_left = cur->_right;
						else
							parent->_right = cur->_right;
					}
					delete cur;
					return true;
				}
				else if (cur->_right == nullptr)
				{
					if (parent == nullptr)
					{
						_root = cur->_left;
					}
					else
					{
						if (parent->_left == cur)
							parent->_left = cur->_left;
						else
							parent->_right = cur->_left;
					}
					delete cur;
					return true;
				}
				else {
					// 2个孩⼦的情况
					// 删除情况4，替换法删除
					// 假设这⾥我们取右⼦树的最⼩结点作为替代结点去删除
					// 这⾥尤其要注意右⼦树的根就是最⼩情况的情况的处理，对应课件图中删
					除8的情况
						// ⼀定要把cur给rightMinP，否会报错。
						Node* rightMinP = cur;
					Node* rightMin = cur->_right;
					while (rightMin->_left)
					{
						rightMinP = rightMin;
						rightMin = rightMin->_left;
					}
					cur->_key = rightMin->_key;
					if (rightMinP->_left == rightMin)
						rightMinP->_left = rightMin->_right;
					else
						rightMinP->_right = rightMin->_right;
					delete rightMin;
					return true;
				}
			}
		}
		return false;
	}
	void InOrder()
	{
		_InOrder(_root);
		cout << endl;
	}
private:
	void _InOrder(Node* root)
	{
		if (root == nullptr)
		{
			return;
		}
		_InOrder(root->_left);
		cout << root->_key << " ";
		_InOrder(root->_right);
	}
	
 private:
	 Node * _root = nullptr;
	 };


	 template < class K, class V>
	  struct BSTNode
		  {
		  // pair<K, V> _kv;
		  K _key;
		  V _value;
		  BSTNode<K, V>* _left;
		  BSTNode<K, V>* _right;
		 
			 BSTNode(const K & key, const V & value)
			 :_key(key)
			 , _value(value)
			 , _left(nullptr)
			 , _right(nullptr)
		 {}
	 };
	 template<class K, class V>
	 class BSTree
	 {
		 typedef BSTNode<K, V> Node;
	 public:
		 BSTree() = default;
		 BSTree(const BSTree<K, V>& t)
		 {
			 _root = Copy(t._root);
		 }
		 BSTree<K, V>& operator=(BSTree<K, V> t)
		 {
			 swap(_root, t._root);
			 return *this;
		 }
		 ~BSTree()
		 {
			 Destroy(_root);
			 _root = nullptr;
		 }
		 bool Insert(const K& key, const V& value)
		 {
			 if (_root == nullptr)
			 {
				 _root = new Node(key, value);
				 return true;
			 }
			 Node* parent = nullptr;
			 Node* cur = _root;
			 while (cur)
			 {
				 if (cur->_key < key)
				 {
					 parent = cur;
					 cur = cur->_right;
					
				 }
				 else if (cur->_key > key)
				 {
					 parent = cur;
					 cur = cur->_left;
				 }
				 else
				 {
					 return false;
				 }
			 }
			 cur = new Node(key, value);
			 if (parent->_key < key)
			 {
				 parent->_right = cur;
			 }
			 else
			 {
				 parent->_left = cur;
			 }
			 return true;
		 }
		 Node* Find(const K& key)
		 {
			 Node* cur = _root;
			 while (cur)
			 {
				 if (cur->_key < key)
				 {
					 cur = cur->_right;
				 }
				 else if (cur->_key > key)
				 {
					 cur = cur->_left;
				 }
				 else
				 {
					 return cur;
				 }
			 }
			 return nullptr;
		 }
		 bool Erase(const K& key)
		 {
			 Node* parent = nullptr;
			 Node* cur = _root;
			 while (cur)
			 {
				 if (cur->_key < key)
				 {
					 parent = cur;
					 cur = cur->_right;
				 }
				 else if (cur->_key > key)
				 {
					 parent = cur;
					 cur = cur->_left;
				 }
				 else
				 {
					 if (cur->_left == nullptr)
					 {
						 if (parent == nullptr)
						 {
							 _root = cur->_right;
						 }
						 else
						 {
							 if (parent->_left == cur)
								 parent->_left = cur->_right;
							 else
								 parent->_right = cur->_right;
						 }
						 delete cur;
						 return true;
					 }
					 else if (cur->_right == nullptr)
					 {
						 if (parent == nullptr)
						 {
							 _root = cur->_left;
						 }
						 else
						 {
							 if (parent->_left == cur)
								 parent->_left = cur->_left;
							 else
								 parent->_right = cur->_left;
						 }
						 delete cur;
						 return true;
					 }
					 else
					 {
						 Node* rightMinP = cur;
						 Node* rightMin = cur->_right;
						 while (rightMin->_left)
						 {
							 rightMinP = rightMin;
							 rightMin = rightMin->_left;
						 }
						 cur->_key = rightMin->_key;
						 if (rightMinP->_left == rightMin)
							 rightMinP->_left = rightMin->_right;
						 else
							 rightMinP->_right = rightMin->_right;
						 delete rightMin;
						 return true;
					 }
				 }
			 }
			 return false;
		 }
		 void InOrder()
		 {
			 _InOrder(_root);
			 cout << endl;
		 }
private:
	void _InOrder(Node* root)
	{
		if (root == nullptr)
		{
			return;
		}
		_InOrder(root->_left);
		cout << root->_key << ":" << root->_value << endl;
		_InOrder(root->_right);
	}
	void Destroy(Node* root)
	{
		if (root == nullptr)
			return;
		Destroy(root->_left);
		Destroy(root->_right);
		delete root;
	}
	Node* Copy(Node* root)
	{
		if (root == nullptr)
			return nullptr;
		Node* newRoot = new Node(root->_key, root->_value);
		newRoot->_left = Copy(root->_left);
		newRoot->_right = Copy(root->_right);
		return newRoot;
	}
private:
	Node* _root = nullptr;
};

//
//
//int main()
//{
//	BSTree<string, string> dict;
//	//BSTree<string, string> copy = dict;
//	dict.Insert("left", "左边");
//	dict.Insert("right", "右边");
//	dict.Insert("insert", "插⼊");
//	dict.Insert("string", "字符串");
//	string str;
//	while (cin >> str)
//	{
//		auto ret = dict.Find(str);
//		if (ret)
//		{
//			cout << "->" << ret->_value << endl;
//		}
//		else
//		{
//			cout << "⽆此单词，请重新输⼊" << endl;
//		}
//	}
//	return 0;
//}
//int main()
//{
//	string arr[] = { "苹果", "西⽠", "苹果", "西⽠", "苹果", "苹果", "西⽠", "苹
//	果", "⾹蕉", "苹果", "⾹蕉" };
//	BSTree<string, int> countTree;
//	for (const auto& str : arr)
//	{
//		// 先查找⽔果在不在搜索树中
//		// 1、不在，说明⽔果第⼀次出现，则插⼊<⽔果, 1>
//		// 2、在，则查找到的结点中⽔果对应的次数++
//		//BSTreeNode<string, int>* ret = countTree.Find(str);
//		auto ret = countTree.Find(str);
//		if (ret == NULL)
//		{
//		countTree.Insert(str, 1);
//		}
//		else
//		{
//		ret->_value++;
//		}
//		}
//		countTree.InOrder();
//		return 0;
//	}